Stencil cutouts include 16 lines (50mm length) separated every 22.5 degrees, and a center and secondary hole to align a cutout with a 50ml conical tube.
Stencil has been tested on VWR and Falcon 150mm diameter petri dishes, with a moderately-used Fine Point Permanent Marker (Sharpie).
Adapted for use in Spiral Gradient Dilution as described in Forster et al. 2004.
The author marked this model as their own original creation.